A research line at IEEC-ICE that has been recently started is related to exoplanets, or planets circling around other stars. So far, about 200 such planets have been discovered. These planets are of Jovian type (similar to Jupiter), meaning gaseous planets with masses much larger than Earth. Most of them have had their orbits measured from observations of the radial velocity of their host star. Researchers I. Ribas and J. Miralda have investigated a correlation of these planets between their masses and their orbital eccentricities, and also between their masses and the metallicity of the host star. A simple idea has been proposed to account for these correlations that postulates two populations of planets: one forms directly by collapse of gas and makes massive planets on eccentric orbits, and the other forms low-mass planets starting from rock-ice cores on circular orbits (which can later acquire an eccentricity by dynamical processes), preferentially in stars of high metallicity. Further work is being planned for investigating these correlations and their implications for the origin of exoplanets in more detail.
In the context of the origin of the terrestrial planets, researcher J.M. Trigo-Rodríguez is working on the early stages of planetary formation in the Solar System. He is currently studying the physicochemical properties of minor bodies (comets, asteroids and meteoroids) in order to determine their link with primitive meteorites, such as the chondrites. Studies of meteorites in collaboration with J. Llorca can yield an insight on protoplanetary disks and the first stages of planetary accretion, including terrestrial enrichment of water and organic matter, because meteorites are aggregates of the solar system primeval components. Among these components we can find presolar grains that are studied by M. Hernanz. These tiny components provide clues on stellar nucleosynthesis processes occurred in the galactic environment where the solar system formed.
Additionally, the study of meteors and fireballs provides valuable data on the physical properties and orbits of meteoroids arriving to the Earth. These particles that are mainly reaching the Earth from comets and asteroids provide additional information on the structure of these so-called "minor bodies", together with clues on the sources of meteorites and Near Earth Objects (NEOs). In this context, a CCD and video all-sky network is being developed for recording meteor and fireball events that will allow to obtain dynamic information on these particles, and trajectory data that would offer the recovery of new meteorites. In fact, in the framework of this research network were recovered the meteorites Villalbeto de la Peña (2004) and Puerto Lápice (2007), two fascinating rocks currently under study.
Gràfics
Among the most primitive meteorites, we have been working in the fascinating carbonaceous chondrites. They are "cosmic sediments" containing small objects that were forming the protoplanetary disk, just before the planets formed by accretion of this kind of materials. The picture shows a thin section of the famous CM chondrite Murchison that contains chondrules, refractory inclusions, and even tiny presolar grains arrived from nearby stars (Trigo-Rodríguez et al., 2006).
We are continuously recording the appearance of meteors and fireballs in the sky by using a high-resolution all-sky CCD camera (Trigo-Rodríguez et al., 2005). These cameras are very sensitive and they can be used even in bad conditions, like e.g. clouds and full Moon (bright feature in the image). This image of the full sky (some horizon details are clearly shown) shows a 2006 Perseid fireball imaged from Montsec Astronomical Observatory (OAdM) last Aug. 12, 2006. Stereoscopic images of a same meteor from several stations allow to reconstruct the atmospheric trajectory and heliocentric orbit of these particles usually coming from comets and asteroids. The square appears magnified in the lower-right corner in order to better show the meteor. It appears segmented as a consequence of being used an inner rotating shutter in order to measure the velocity and deceleration of the meteor in the atmosphere. The original picture is about 33Mb in size.
To obtain a precise description of the formation, structure and evolution of exoplanets it is necessary to measure their orbital and physical properties but also to characterize their environments, which are dominated by the emissions of the parent stars. Thus, we intend to analyse the fundamental properties and the orbital elements of the known exoplanets to study their correlations with the properties of the parent star and to evaluate the hypothesis of the existence of two populations. Also, we plan to study the evolution of the high-energy irradiancies and of the particle emissions of GKM stars during the main sequence, and to estimate their short- and mid-term variability.
PI i Co-PI: Ribas, I. Participants: Morales, J.C., J. Miralda Institució Financiadora: MEC - Plan Nacional de Astronomía y Astrofísica
This project is devoted to the study of low mass objects (very low mass stars, brown dwarfs, and exoplanets) in close binaries and in planetary systems. The main goal is to better understand the effects of the interactions between the binary components (either star or planet) that may alter their internal structure. Eclipsing binaries and transiting planet systems are excellent laboratories for such studies because the masses and radii of the components can be measured to great accuracy.
PI i Co-PI: Ribas, I. Participants: Morales, J.C., Jordi, C., Baraffe, I., Chabrier, G., Gallardo, J., Giménez, A. Institució Financiadora: MEC- Acciones Integradas Atres Institucions: CRAL (Lyon, France)
Our present view of the stellar habitable zone is incomplete. Only by characterising the emissions of the entire population of low-mass stars and by understanding the interactions of their radiation and particle fluxes with planetary atmospheres will we be able to complete the true picture of the habitable zone around a star. In more detail, we are working to attain a comprehensive picture of the long-term and short-term evolution of XUV radiation and particle emissions of a wide range of low-mass stars. Besides the astrophysical importance of the study, the resulting fluxes are a critical ingredient to understand the shaping, evolution and ultimate fate of planetary atmospheres. One crucial parameter in upper atmospheres affected by hydrodynamic escape is their expansion, which is controlled by the XUV heat input. We will apply a hydrodynamic model, which will yield a better estimation of the expansion radius and the resulting thermal escape fluxes. Finally, we are studying the star-planet connection with numerical codes that simulate the consistent evolution of an irradiated atmosphere and compute a synthetic spectrum of the planet.
PI i Co-PI: Ribas, I. Participants: Selsis, F., Montesinos, B., Eiroa, C., Lammer, H., Lichtenegger, H.I., Jaritz, G., Amerstorfer, U., Endler, S., Odert, P., Leitzinger, M. Institució Financiadora: MEC- Acciones Integradas Atres Institucions: OAW (Austria)
Morales, J. C., Ribas, I., Jordi, C., Torres, G., Gallardo, J., Guinan, E. F., Charbonneau, D., Wolf, M., Latham, D. W., Anglada-Escudé, G., et al, Absolute Properties of the Low-Mass Eclipsing Binary CM Draconis, Astrophysical Journal, 691, pp. 1400-1411, 2009, feb, binaries: eclipsing, binaries: spectroscopic, stars: late-type, stars: fundamental parameters, stars: individual: CM Dra, 0810.1541, 10.1088/0004-637X/691/2/1400
Font-Ribera, A., Miralda Escudé, J., Ribas, I., Protostellar Cloud Fragmentation and Inward Migration by Disk Capture as the Origin of Massive Exoplanets, Astrophysical Journal, 694, pp. 183-191, 2009, mar, methods: N-body simulations, planetary systems, planetary systems: formation, 0806.4174, 10.1088/0004-637X/694/1/183
Degroote, P., Aerts, C., Ollivier, M., Miglio, A., Debosscher, J., Cuypers, J., Briquet, M., Montalbán, J., Thoul, A., Noels, A., Ribas, I., et al, CoRoT's view of newly discovered B-star pulsators: results for 358 candidate B pulsators from the initial run's exoplanet field data, Astronomy & Astrophysics, 506, pp. 471-489, 2009, oct, methods: data analysis, stars: oscillations, stars: variables: general, 0907.2183, 10.1051/0004-6361/200911884
Kaiser, A., Weiss, W., Guenther, E., Balaguer, L., Maceroni, C., Ribas, I., The Domain of $\delta$ Scuti Stars: First CoRoT IRa01 Results, American Institute of Physics Conference Series, J. A. Guzik & P. A. Bradley, , 1170, American Institute of Physics Conference Series, pp. 432-434, 2009, sep, oscillations, variable stars, stars, Pulsations, oscillations, and stellar seismology, Variable and peculiar stars, Main-sequence: intermediate-type stars, 10.1063/1.3246536
Uytterhoeven, K., Poretti, E., Mathias, P., Amado, P., Rainer, M., Martín-Ruiz, S., Rodríguez, E., Paparó, M., Pollard, K., Maceroni, C., Ribas, I., et al, The asteroseismic ground-based observational counterpart of CoRoT, American Institute of Physics Conference Series, J. A. Guzik & P. A. Bradley, , 1170, American Institute of Physics Conference Series, pp. 327-329, 2009, sep, variable stars, spectrophotometry, photometry, Cepheids, Spectroscopy and spectrophotometry, Photometric, polarimetric, and spectroscopic instrumentation, 10.1063/1.3246506
Lefèvre, L., Michel, E., Aerts, C., Kaiser, A., Neiner, C., Poretti, E., Garrido, R., Baglin, A., Auvergne, M., Catala, C., Ribas, I., et al, Instability domains of $\delta$ Scuti and Slowly Pulsating B stars : How will the CoRoT satellite help to determine the limits ?, Communications in Asteroseismology, 158, pp. 189-+, 2009, jul
Degroote, P., Miglio, A., Debosscher, J., Montalbán, J., Cuypers, J., Briquet, M., De Cat, P., Thoul, A., Morel, T., Niemczura, E., Ribas, I., et al, Space observations of B stars with CoRoT, Communications in Asteroseismology, 158, pp. 167-+, 2009, jul
Kipping, D. M., Ribas, I., Font-Ribera, A., Eccentric Planets \amp Transit Time Variation, IAU Symposium, 253, IAU Symposium, pp. 490-491, 2009, feb, 10.1017/S1743921308027014
Odert, P., Leitzinger, M., Hanslmeier, A., Lammer, H., Khodachenko, M. L., Ribas, I., Vanko, M., Konovalenko, A. A., Rucker, H. O., A catalogue of nearby M stars, American Institute of Physics Conference Series, E. Stempels, , 1094, American Institute of Physics Conference Series, pp. 947-950, 2009, feb, astronomical atlases, brown dwarfs, stellar atmospheres, 10.1063/1.3099275
Martínez-Arnáiz, R. M., Maldonado, J., Montes, D., Eiroa, C., Montesinos, B., Ribas, I., Solano, E., High resolution spectroscopic characterization of the FGK stars in the Solar neighbourhood, American Institute of Physics Conference Series, E. Stempels, , 1094, American Institute of Physics Conference Series, pp. 465-468, 2009, feb, extrasolar planets, chromosphere, star formation, 10.1063/1.3099149
Ribas, I., Miralda, J., The eccentricity-mass distribution of exoplanets: signatures of different formation mechanisms?, Astronomy & Astrophysics, 464, pp. 779-785, 2007, mar, 10.1051/0004-6361:20065726
Ribas, I., Masses and Radii of Low-Mass Stars: Theory Versus Observations, Astrophysics and Space Science, 304, pp. 89-92, 2006, aug, 10.1007/s10509-006-9081-4
Ribas, I., Morales, J. C., Prieto, C. A., Jordi, C., Bradstreet, D. H., Sanders, S. J., First Results from ROTES: The ROtse Telescope Eclipsing-binary Survey, Astrophysics and Space Science, 304, pp. 231-233, 2006, aug, 10.1007/s10509-006-9119-7
Guillot, T., Santos, N. C., Pont, F., Iro, N., Melo, C., Ribas, I., A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars, Astronomy & Astrophysics, 453, pp. L21-L24, 2006, jul, astro-ph/0605751, 10.1051/0004-6361:20065476
Masana, E., Jordi, C., Ribas, I., Effective temperature scale and bolometric corrections from 2MASS photometry, Astronomy & Astrophysics, 450, pp. 735-746, 2006, may, astro-ph/0601049, 10.1051/0004-6361:20054021
Kulikov, Y. N., Lammer, H., Lichtenegger, H. I. M., Terada, N., Ribas, I., Kolb, C., Langmayr, D., Lundin, R., Guinan, E. F., Barabash, S., et al, Atmospheric and water loss from early Venus, Planetary and Space Science, 54, pp. 1425-1444, 2006, nov, 10.1016/j.pss.2006.04.021
Blum, J., Schraepler, R., Davidsson, B. J. R., Trigo-Rodríguez, J. M., The Physics of Protoplanetesimal Dust Agglomerates I. Mechanical Properties and Relations to Primitive Bodies in the Solar System
, Astrophysical Journal, 652, pp. 1768-1781, 2006
Trigo-Rodríguez, J. M., Llorca, J., Cometary meteoroids strength: clues to the structure and evolution of comets. , Monthly Notices of the Royal Astronomical Society, 372, 2, pp. 655-660, 2006
Trigo-Rodríguez, J. M., Rubin, A. E., Wasson, J. T., Non-nebular origin of dark mantles around chondrules and inclusions in CM chondrites, Geochimica et Cosmochimica Acta, 70, pp. 1271-1290, 2006, mar
Trigo-Rodríguez, J. M., Borovi\v cka, J., Spurn\'y, P., Ortiz, J. L., Docobo, J. A., Castro-Tirado, A. J., Llorca, J., The Villalbeto de la Peña meteorite fall: II. Determination of atmospheric trajectory and orbit, Meteoritics and Planetary Science, 41, pp. 505-517, 2006, apr
Llorca, J., Trigo-Rodríguez, J. M., Ortiz, J. L., Docobo, J. A., García-Guinea, J., Castro-Tirado, A. J., Rubin, A. E., Eugster, O., Edwards, W., Laubenstein, M., et al, The Villalbeto de la Peña meteorite fall: I. Fireball energy, meteorite recovery, strewn field, and petrography, Meteoritics and Planetary Science, 40, pp. 795-+, 2005, jun
Ribas, I., Guinan, E. F., Güdel, M., Audard, M., Evolution of the Solar Activity over Time and Effects on Planetary Atmospheres. I. High-Energy Irradiances (1-1700 \AA), Astrophysical Journal, 622, pp. 680-694, 2005, mar, astro-ph/0412253, 10.1086/427977
Grie\ssmeier, J. -., Stadelmann, A., Penz, T., Lammer, H., Selsis, F., Ribas, I., Guinan, E. F., Motschmann, U., Biernat, H. K., Weiss, W. W., The effect of tidal locking on the magnetospheric and atmospheric evolution of ``Hot Jupiters'', Astronomy & Astrophysics, 425, pp. 753-762, 2004, oct, 10.1051/0004-6361:20035684
Lammer, H., Ribas, I., Grie\ssmeier, J. -., Penz, T., Hanslmeier, A., Biernat, H. K., A brief history of the solar radiation and particle flux evolution, Hvar Observatory Bulletin, 28, pp. 139-155, 2004
Lammer, H., Selsis, F., Ribas, I., Guinan, E. F., Bauer, S. J., Weiss, W. W., Atmospheric Loss of Exoplanets Resulting from Stellar X-Ray and Extreme-Ultraviolet Heating, Astrophysical Journal Letters, 598, pp. L121-L124, 2003, dec, 10.1086/380815
Ribas, I., Solano, E., Masana, E., Giménez, A., Effective temperatures and radii of planet-hosting stars from IR photometry, Astronomy & Astrophysics, 411, pp. L501-L504, 2003, dec, astro-ph/0310456, 10.1051/0004-6361:20031626
Guinan, E. F., Ribas, I., Harper, G. M., Far-Ultraviolet Emissions of the Sun in Time: Probing Solar Magnetic Activity and Effects on Evolution of Paleoplanetary Atmospheres, Astrophysical Journal, 594, pp. 561-572, 2003, sep, astro-ph/0305279, 10.1086/376859
Lammer, H., Lichtenegger, H. I. M., Kolb, C., Ribas, I., Guinan, E. F., Abart, R., Bauer, S. J., Loss of water from Mars:Implications for the oxidation of the soil, Icarus, 165, pp. 9-25, 2003, sep, 10.1016/S0019-1035(03)00170-2
Ribas, I., Arenou, F., Guinan, E. F., Astrometric and Light-Travel Time Orbits to Detect Low-Mass Companions: A Case Study of the Eclipsing System R Canis Majoris, Astronomical Journal, 123, pp. 2033-2041, 2002, apr, astro-ph/0201148, 10.1086/339560
Miralda, J., Orbital Perturbations of Transiting Planets: A Possible Method to Measure Stellar Quadrupoles and to Detect Earth-Mass Planets, Astrophysical Journal, 564, pp. 1019-1023, 2002, jan, 10.1086/324279
Guinan, E. F., Ribas, I., The Best Brown Dwarf Yet? A Companion to the Hyades Eclipsing Binary V471 Tauri, Astrophysical Journal Letters, 546, pp. L43-L47, 2001, jan, astro-ph/0010487, 10.1086/318065
contribucions a conferències
Trigo-Rodríguez, J. M., Madiedo J.M., Castro-Tirado A.J., Llorca J., and Troughton, B. , 2007 fireball activity imaged by the Spanish Fireball Network: identifying meteorite delivery sources, 3th European Planetary Science Congress (EUROPLANET), Münster, Germany, Contributed talk, 2008-09-21, 2008-09-26
Guinan, E.F., Engle, S., Ribas, I., Harper, G., FUSE Observations of Young to Old dG, dK & dM Stars: Critical Tests of Dynamos, X-FUV Irrandiances and Impacts on Planetary Environments and the Development of Life, 207th Meeting of the American Astronomical Society, Washington, DC (USA), Poster, 2006-01-08, 2006-01-12
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